7.10.4.a seconds() function
You should see '0' for seconds('P1Y2M').
seconds('P1Y2M') :
You should see '297001.5' for seconds('P3DT10H30M1.5S').
seconds('P3DT10H30M1.5S') :
You should see 'NaN' for seconds('3').
seconds('3') :